Based on the quantum invariant theory, the quantum phases, including the total phase as well as its dynamical and geometric parts, of Pancharatnam type are derived for a general spin in a time-dependent magnetic field, without the constraint of adiabatic, cyclic or unitary condition. The geometric meaning of geometric phase is expounded.

The which-path micromaser detector and the associated quantum eraser are proposed based on the interactions of atoms with a cavity placed in front of one of the double slits in an atomic interferometer.

The relations between Wehrl’s entropy and squeezing or total noise in the field with Gaussian Q function are established, The results show that, the Wehrl’s entropy will be reduced when the squeezing is increased or the total noise is decreased. The other nonclassical properties in this kind of field are also discussed.

By the aid of the generalized linear quantum transform theory, we present for the multimode boson exponential quadratic operators two theorems to change the operator expressions among usual, normal and anti-normal orderings.

Two identical chaotic systems of conservative flow are shown to be synchronous by applying periodic pubes at a regular time interval. This idea is illustrated with a numerical example. It is robust against external noise.

A generalized Frenkel-Kontorova model with the Morse potentials is studied. The phase diagram reflects the nonlinear nature of the Morse potential. The correspondences of the ground states and the orbits of the area-preserving map are studied numerically. Our results present a better simulation to the real systems.

Nonlinear feedback functional method for controlling spatiotemporal chaos is presented. As a key point, some typical kinds of nonlinear feedback functions are given. The efficiency and robustness of the method based on the flexibility of choices of nonlinear feedback functions are discussed.

The first extensive electron momentum spectroscopy study of the satellite structure in the inner valence region of methane at 1200eV is reported. The experimental momentum profiles belonging to the (2a₁)^-1 satellite state are presented at energies 25.3, 28.5, 31.5, 35.5eV, and compared with the 146-G(CI) calculation.

The zero-order diffraction of phase grating mask is analysed for rectangular and sinusoidal corrugated profiles, and a novel method is proposed for determining the depth and duty cycle parameter by the diffraction measurement at different wavelengths.

we present an analysis for the alternating linear polarization (ALP) state in a multi-longitudinal-mode laser with external modulation, and propose a new method for detecting this state. In a neodymium-doped fiber laser with a modulated pump, the ALP state is experimentally observed at both periodic and chaotic oscillation.

Two-beam coupling and self-pumped phase conjugation properties of a Rh-doped BaTiO₃ crystal were investigated at 633nm as the temperature was increased from 20 to 50°C. A significant decrease in response time and an increase in gain of two-beam coupling were obtained. The self-pumped phase conjugation reflectivity was increased from 45 to 64% in this temperature range.

The photorefractive effect was observed in poly(N-vinylcarbazole) composite films doped with electro-optic chromophore 2,5-dimetly-4(p-nitrophenylazo) anisole, plasticizer N-ethylcarbazole and different content fullerene C₆₀. Their two-beam coupling experiment was performed by using a cw He-Ne laser at 632.8nm. The two-beam-coupling gain coefficient as higher as 140cm^-1 was measured at poling dc electric field of 76V/μm and it was also found to be relied on the content of photosensitizer C₆₀.

Perturbations about kink solution of Ф- 4 equation are investigated by a direct approach which was recently developed in a study of soliton perturbation theory. In this scheme, the derivative expansion method from classical perturbation theory is employed to linearize the perturbed equation. The solution of the linearized equation for first-order correction is derived by the method of Laplace transformation. At the same time, the parameters variation is obtained directly from the secularity conditions.

In this letter, we report a novel phenomenon of photoisomerization-induced changes in liquid crystalline azobenzene polymers P12 Langmuir-Blodgette monolayer deposited on gold film by irradiating the monolayer with UV(360nm) and blue (450nm) lights, which was investigated by surface plasmon resonance technique. It has been shown that it is possible to switch the refractive indices reversibly by irradiating these films with light of appropriate wavelength.

A nonlinear optimization method is proposed to inverse the sea-bottom properties. The method is called seed division algorithm (SDA) and can be used to solve global optimization problem. A numerical test is carried out to inverse the sea-bottom properties. The test is based on SDA and beam displacement ray mode theory.

In the observations of Freja satellite in the energization region of the low aurora (1700 km), a new nonlinear plasma oscillation with a turbulent spectrum at the fractional harmonics of the local proton gyrofrequencies is reported and analyzed with the wavelet transformation in the time-frequency spectrum.

The dispersion relation of the ion acoustic wave in an intense laser field is obtained by using a nonequilibrium distribution function. The Brillouin scattering instability is examined by numerical method.

Ta and C ions extracted from a metal vapor vacuum arc ion source were implanted into H21 steel, with an implantation dose of 3 x 10¹⁷cm^-2, extraction acceleration 42kV, and average ion beam flux about 40μA.cm^-2. Rutherford backscattering spectrum was used to measure the surface composition after Ta or Ta+C implantation. Observation of phase induced by Ta and C implantation was carried out by x-ray diffraction analysis. Experimental results showed that the wear rate of the implanted layer dropped 30% for Ta ion implantation and by a factor of 2.5 for Ta+C dual ion implantation. Thus Ta+C dual ion implantation was found to significantly reduce the friction coefficient of H21 steel. The wear mechanisms of the implanted layer were discussed.

An asymptotic expression for the density oscillation induced by an interface has been derived analytically by using a method which is equivalent to stationary phase approximation. The effects of the geometric structure of the Fermi surface and reflected amplitude are shown explicitly. The results provide a model-independent interpretation for some common features observed recently in the magnetic multilayer experiments.

The origin of the fine structure of ultraviolet and visible absorption spectra of silicon nanocolloids in 2-propanol prepared in Ar atmosphere by a new sputtering method is studied. The fine structure is described by phonon-electron coupling in electron transition of silicon. On the basis of the structure model of Si-Si_4-nO_n(n = 0, 1,2,3,4), an energy relation has been proposed to explain the fine structure. The fine structure indicates strong multiple phonon absorption which depends on that how many oxygen atoms the silicon atom bonds to.

Si-Si_l-xGe_x-Ge heterostructures with Ge fraction graded linearly from 1 to 0 have been epitaxially grown on Ge substrates by rapid, thermal process/very low pressure-chemical vapor deposition. The peak value of the spectrum response for these structures ranges from 1.3 to 1.55 μm, which is just in accordance with the optical fiber communication window, and considered to be the superposition of the response in Si_l-xGe_x absorption region and the Ge absorption region. High detecting sensitivity, and low dark current have been achieved from the prototype SiGe ptype intrinsic n-type photodetectors made of these structures.